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Mechanical Advantage

Jaw Types

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It seems there are two basic types of jaws our there - those that use the cam action to spread the rear of the jaws apart, thereby pinching the tips together (Renzetti, Nor-Vise), and those that push/pull the jaws within a tube to close the gap (Dyna-King pushes, while Peak pulls).

 

I know both can perform well, and there are very nice versions of either. But I'd like to hear from those who have experiences with both - are there any pros/cons to either types of jaws? Do you prefer one over the other?

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I generally tie about the same size fly most of the time, so I prefer the cam action type. Just a little faster and easier on the fingers.

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IMO, the other traits of a vise have as much more of a bearing on the choice of "vise X" over "vise Y" than does jaw type (i.e., 2-pc jaw vs draw-collet jaw). Over the years, vises with jaws of either type have been made that function impressively and poorly.

 

A third type of jaw you don't mention is the "spring" jaw which remains under constant tension (i.e., Regal and its imitators). Though there are only a few vises with this jaw type, it's apparent that tyers who do opt for such a vise do so because they favor the these jaws over other types for ease of operation.

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I started on the cylinder pull close style jaws. These were on a budget vice and were ok but the variety of hook size was poor and rotation was near impossible without the jaw working loose. A more top end vice may have been better than this though.

Now I tie on a Cam with a serrated jaw and am more than pleased. Changing the jaw gape for bigger/smaller hooks takes a second and I tie a set of flies at a time so I'm not chopping and changing sizes every fly.

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My vise is one of these.

 

 

I have had this vise since ... the 80's ... I think !

 

It still holds the hooks and I cannot complain about it at all.

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There are five kinds of vice jaw clamping systems I am aware of for holding hooks. You have included two under one heading, but from an engineering point of view they are significantly different.

 

Pull into collet, Push into collet, Spring, Two plates and a pivot. Loop and grove.

 

In my time tying flies I've owned the first 4, and tied on the last one.

 

Pull into collet type (Thompson and copies, HMH etc.) These hold the jaws under tension. Steel, which most jaws are made from is not at its strongest under tension. The quality vices overcome any problems by using materials that will stand up to the forces involved in fly tying. The failure points tend to be around the cam attachment and the hinge points at the bottom of the slot between the jaws. The repetitive bending at that point has been known to break jaws at the bottom of the bifurcation.

 

Push into collet (Dyna-King) The jaws are under compression so are stronger. The cam is not attached to the jaw and has a larger surface area of cam bearing the load.

 

Both these two kinds of vice have two distinct problems. They require the metal of the jaw to be bent during the jaw action. If quality steel is used this isn't a problem, the bending takes place within the elastic limits of the material. I have seen quite a few cheaper vice jaws that have broken at the bend point. The other problem is access to the insides of the jaws. Many years ago there was a debate over whether or not jaws should be hardened. It seems that all vice jaws are now hardened. With jaws that are made from 1 piece of steel access to the insides of the jaw, which is the load bearing surface, is restricted. This makes it much more difficult to harden the jaws well. These are all problems that are overcome by use of higher quality materials on better vices. They are, though, the usual fail points on cheaper vices.

 

Sprung Jaws (Regal and copies) limit the movement of the jaws by the size of the cam so you can not overstress them. The only problem they suffer is brittleness at the very tips of the jaws. Many people have pointed out that the jaws can be chipped with a small hook in the very tips of the jaws. Regal overcome this with the quality of material.

 

Two plates and a pivot. (Renzetti, LAW, J Vise etc.) This method gives the greatest mechanical advantage when clamping the hook. The plates do not bend as they act around the pivot. The way the hook is held is the same way a work piece is clamped to the bed of a milling machine. The forces used there thousands of times greater than in tying. As the jaws are made of separate pieces there is no problem accessing any area of the jaw to harden them.

 

Loop and grove (Smowbee AR vice etc.) Here a loop of metal pulls the bend of the hook into a grove. This is a novel idea but unfortunately not suited the the forces used in fly tying. Repetitive sideways movement loosens the hook. If you put a long shank hook into one of these vices and run down the hook shank with touching turns of thread you will pull the hook from side to side with teach turn. Do this moderately quickly, and the hook will loosen.

 

In choosing a vice my first consideration, before how the hook is held, is access to the hook. The dream would be this. Imagine fly tying being featured in an episode of Star Trek. There would be a small plate on the table top emitting some kind of force that held the hook in space 8 inches or so above it. You would have total access to the hook. That is the ideal vice, anything else is a compromise. As we can't do that yet it is a case of finding the best compromise you can find. It may well be different for you, than it is for me.

 

Cheers,

C.

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Crackaig lays out your choices nicely. Have tied on all but the "loop and grove" (groove?) and prefer by far and away the "two plates and a pivot" for the ease of adjustment, and the "sprung jaws" for the speed of adjustment. Collet jaws take too much work to adjust, IMHO, but they do hold a hook well...sometimes too well. If you get the adjustment wrong on a pull collet like the Dyna-King, for example, you can crush the hook quite easily. A useful feature when tying big flies, less useful for small ones. YMMV.

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I have used 4 of the different clamping systems. My first two vises were Thompson's (the real ones made in Elgin IL.) I used a Thompson A for years, and "upgraded" to a Thompson Pro. Both these vises are still in use, after more than 50 years on the A, and 35 on the Pro. They both hold hooks just fine.

 

I have used the Regal chipped the jaws, and got rid of it. I know that chipping the jaws was only a problem when trying to place very tiny hooks. If placed well back in the jaws, the vise would hold even size 28 or 32 hooks, but your access to the hooks was restricted. Newer jaw styles from Regal have addressed this issue.

 

My Dyna-King is a great vise, and is a push collet system. The jaws are also slotted (rather than grooved,) for larger hooks. The clamping lever has a positive click feature that lets you know when the hook is properly clamped in the jaws. Of the collet type vises, I like the Dyna-King best.

 

For more than 20 years now, I have been using the Nor-vise. The Nor-vise is an example of the plates and pivot system. I tie 90 to 95% of my flies on the Nor-vise, and it works for me.

 

Crackaig has pointed out some of the problems and advantages of each of these system quite well. Of the 5 different types of clamping mechanisms available, 4 do a more than adequate job. The problems with many of the clamping systems is not in the system itself (push, pull, plate, and pivot, and spring,) but in the materials used in the jaws.

 

Cheap vises fail not because there isn't enough clamping force, but because there is enough mechanical advantage in most of these systems to bend and over stress cheap steel.

 

Today, there are dozens and dozens of very good quality affordable vises. Many of them are made in the USA. Several comes from Europe, and one is from South Africa. From that very large geographic area, you should be able to find a vise that will out last you, and still be clamping down and holding hooks for your grand kids.

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There is a sixth type. An example would be the Xuron. The jaw is a single slotted piece, closed by a screw.

 

The collet type could also be divided into the cam lever type (Thomson A, Dyna King) and the knob type (Thompson B, Price Vise). I don't know if anyone is making the knob type these days. The cam lever type offers more leverage but the knob type does not require adjustment for hook size.

 

I mostly use a Regal for simplicity.

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They used to use this type back around the early part of the last century that I don't think was mentioned either. I was interested in getting one just to see how it works till I read that it sucks at holding smaller hooks easily. Theodore Gordon used this one supposedly.

 

Regards,

Mark

 

 

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